Wireways or wiring ducts are used in factories to guide and support electrical wiring in an orderly manner and to protect the wires from the dust and fluids commonly found in industrial environments. A common form of wireway employs elongated U-shaped troughs having end fittings which allow them to connect to other troughs, elbows or tees having similar fittings. These fittings may be joined in a wide variety of combinations to adapt to a particular application.
Often the wireways are used with cords which have connectors or machines secured to their ends before they are to be placed in the troughs. In such situations troughs having knockouts in their sides which may be removed to form passages connected to the tops of the troughs are used so that the cords may be passed into and out of the wireways through the side openings without the need for removing the cords from their machines or connectors. The need exists for such a lay-in wireway which is low in cost, easy to install in industrial environments, and provides good physical protection for wiring in general and cords in particular.